Genetic and environmental factors contributing to instability in grain durability (Year 2)

Candice Hirsch

Grain durability and composition are important factors in considering grain quality for export markets. There are ways to measure or assess durability and composition traits such as broken kernels, percent of whole kernels, total damage, heat damage, stress cracks, 100-kernel weight, density, test weight, percent horneous (hard) endosperm, as well as protein, starch, and oil concentration. Decreased durability and compositional changes in some hybrids are a major concern for export markets as this can impact grade levels as grain moves through the marketing chain. There are many different factors that can contribute to grain quality (durability and composition) including genetics, management practices, and environmental conditions. Here we propose a multifaceted approach to address grain quality challenges that are faced by Minnesota Corn Growers. The first approach is to identify genes controlling stability in compositional traits across environments. This will complement existing studies that have identified genes controlling these traits in single environments or averaged across environments. This first approach will help identify breeding targets for grain quality stability in order to provide a more consistent high-quality product. The second approach is to conduct a state-wide multi-environment on-farm trial dissecting properties of the grain (e.g. pericarp thickness, compositional traits, ratio of hard-tosoft endosperm, etc.) to understand the degree to which hybrids, environments, and management practices are contributing to quality variation, and to determine what specific properties of the grain affect variation in durability. The final approach will assess historical changes to in-season environmental responsiveness that contribute to increased variability in quality of corn grain and forecast future trends using a set of hybrids that were developed in the 1950’s through current elite hybrids. This project is in direct alignment with the Expanded Uses Research Priorities, specifically “Research that addresses corn grain quality and durability challenges domestically and for export.”